RBM39 and cancer: Previous clinical trials have shown that sulfonamides are generally well tolerated, but the observed efficacy in cancer patients was limited.130, 131, 132, 133, 134, 135 Using distinct target identification approaches, the authors concluded that RBM39 is the putative molecular target of sulfonamide compounds including indisulam, E7820, and chloroquinoxaline.136, 137 Mechanistically, the sulfonamides act as molecular glue by targeting RBM39 to the CUL4‐DCAF15 ubiquitin complex for proteasome degradation in a manner that depends on DCAF15 expression level.